Major clinical on/off tissue toxicity effects for CD19-targeted CAR-T cells include cytokine release syndrome (CRS) [98], which is caused by activation of T cells and manifests as high-grade fever, hypertension, and immune effector cell-associate neurotoxicity syndrome (ICANS) which is associated with endothelial cell dysfunction at the blood-brain barrier caused due to hyperinflammation [99,100]. The gene discussed is CD19; the disease is congenital rubella syndrome.